Cap 12

Circuite Basculante Bistabile &LUFXLWHOH EDVFXODQWH VXQW FLUFXLWH HOHFWURQLFH FDUH vQ IXQF LRQDUH DX GRX  VDX PDL PXOWH SXQFWH GH IXQF LRQDUH úL WUHFHUHD GH OD XQ SXQFW OD DOWXO VH IDFH SULQWUXQ SURFHV IRDUWH UDSLG FXPXODWLYGHUHJXO GDWRUDWXQHL UHDF LL SR]LWLYH  FDUH SRDUW  QXPHOH GH

basculare, de unde stabile sau

úL QXPHOH DFHVWRU FLUFXLWH 6W ULOH GH IXQ LRQDUH SH FDUH OH DUH FLUFXLWXO SRW IL

cvasistabile. 6H VSXQH F  R VWDUH GH IXQF LRQDUH D XQXL FLUFXLW HVWH VWDELO  GDF  FLUFXLWXO U PkQH vQ DFHO SXQFW GH IXQF LRQDUH XQ WLPS QHOLPLWDW LDU LHúLUHD GLQ DFHDVW  VWDUH VH IDFH

numai pe baza unei comenzi

prin basculare,

GLQH[WHULRUXO FLUFXLWXOXL 2 VWDUH VWDELO  HVWHWRWGHDXQD DVRFLDW

FXLQWUDUHDFLUFXLWXOXLSHFDUHVHG FRPDQGDGHEDVFXODUHGLQDFHDVWDUH 2VWDUHGHIXQF LRQDUHD XQXL FLUFXLW VH QXPHúWH FYDVLVWDELO  LQVWDELO  GDF  FLUFXLWXO U PkQH vQDFHDVWDUHXQWLPSOLPLWDWúLDSRLI

U YUHRFRPDQG GLQH[WHULRUEDVFXOHD]  vQ DOWDVWDUH

(YLGHQWvQDFHVW VLWXD LHQXPDLHVWHQHYRLHGHQLFLR LQWUDUHGHFRPDQG 7LPSXO OLPLWDWFkW FLUFXLWXO VW  vQ VWDUHD FYDVLVWDELO  HVWH GHWHUPLQDW GH UHJXO  GH XQHOH FRPSRQHQWH LQWHUQH DOH FLUFXLWXOXLUH]LVWHQ HFRQGHQVDWRDUHHWF  'LQ SXQFW GH YHGHUH DO QXP UXOXL úL WLSXOXL GH VW UL vQ PRG X]XDO VH vQWkOQHVF XUP WRDUHOH

circuite : - circuite basculante bistabilevQIXQF LRQDUHSUH]LQW GRX VW ULDPEHOHVWDELOH - circuite basculante monostabileSUH]LQW GRX VW ULXQDVWDELO úLDGRXDFYDVLVWDELO - circuite basculante astabileSUH]LQW GRX VW ULGHIXQF LRQDUHDPEHOHFYDVLVWDELOH



&LUFXLWHEDVFXODQWHELVWDELOHFXWUDQ]LVWRDUHQSQvQFXSODMFROHFWRUED]

1.

6FKHP HOHFWULF IXQF LRQDUH

([LVW  R PDUH GLYHUVLWDWH GH &%% FX WUDQ]LVWRDUH FXSODWH vQ HPLWRU FX WUDQ]LVWRDUH FRPSOHPHQWDUH HWF  ILHFDUH DYkQG VHFWRUXO V X GH DSOLFD LL 'UHSW UHSUH]HQWDWLY VW  úL OD

baza bistabilelor integrate) este circuitul din fig. 1. &RQVWUXF LD

FLUFXLWXOXL

HVWH

SHUIHFW

au fost reprezentate cu linie punct deoarece ele pot lipsi la analiza în

VLPHWULF  &RQGHQVDWRDUHOH &1 úL &2

UHJLP VWD LRQDU HIHFWXO ORU LQWHUYHQLQG

numai în regim dinamic (condensatoare de accelerare). )XQF LRQDUH /D SULPD DOLPHQWDUH GDWRULW  VLPHWULHL FLUFXLWXOXL VH SRDWH SUHVXSXQH F  FHOH GRX  WUDQ]LVWRDUH FRQGXF OD IHO DGLF DX DFHODúL FXUHQW GH FROHFWRU LC1

= iC2 .

$FHDVW  VWDUH vQV  QX UH]LVW  ÌQWU DGHY UVDSUHVXSXQHPF GLQWURFDX]

Fig.1 CBB cu tranzistoare npn cuplaj C-B

H[WHUQ RDUHFDUHFXUHQWXO L C1 FUHúWHÌQ XUPD DFHVWHL PRGLILF UL WHQVLXQHD GLQ

colectorul lui T1 VFDGH VH FDOFXOHD]  FX 8C1 = EC – RC1 ·iC1  6F GHUHD OXL 8C1 se transmite prin divizorul rezistiv R1, r2 în baza lui T2 FHHD FH GHWHUPLQ  VF GHUHD WHQVLXQLL VDOH GH ED]  6HDPRUVHD] PRGLILF ULOHvQODQ GHVFULVHGHGLDJUDPDGHPDLMRVvQFDUH

-

2 V JHDW  RUL]RQWDO  VHPQLILF  WUHFHUHD GH OD FDX]  OD HIHFW GHDVXSUD V JH LL VD LQGLFDWSURFHVXOSULQFDUHVHWUHFHGHODFDX] ODHIHFW 

1

-

6 JHDWD YHUWLFDO  VHPQLILF  VHQVXO GH PRGLILFDUH FUHúWHUHGHVFUHúWHUH  D P ULPLL

respective.

6H REVHUY  F  VH SXQH vQ HYLGHQ

 R UHDF LH SR]LWLY  FDUH vQW UHúWH GH]HFKLOLEUXO LQL LDO

FUHúWHUHDOXL L C1 3URFHVXO VH FRQWLQX  WUDQ]LVWRUXO 71 HYROXkQG VSUH VDWXUD LH 8C1

timp ce T2 HYROXHD]

scade) în

 VSUH EORFDUH 8C2 FUHúWH  0HFDQLVPXO FRQWLQX  vQ DYDODQú  UHDF LH

SR]LWLY  SkQ  vQ PRPHQWXO vQ FDUH ILH 71

devine saturat, fie T2 GHYLQH EORFDW úL UHDF

LD

SR]LWLY  VH vQWUHUXSH ODQ XO GHVFULV PDL VXV VH vQWUHUXSH   &LUFXLWXO HVWH DVWIHO GLPHQVLRQDW

T1 VDWXUDW úL 72 blocat VLQJXUD VLWXD activ – T2 blocat).

vQFkW VH DMXQJH OD VWDUHD ILQDOD FDUDFWHUL]DW  GH GLVWLQFW FDUHDUPDLILSRVLELO DUIL71

LH

6LPLODU VH SRDWH DU WD F  R SHUWXUED LH LQL LDO  GH VHQV FRQWUDU DPRUVHD]  XQ SURFHV GH

basculare care ar duce circuitul în starea T1 blocat – T2 saturat HYLGHQW UHDF

LD SR]LWLY  DU

SXWHDILGHVFULV GHXQODQ GHDFHODúLWLSFDPDLVXV 

ÌQFRQFOX]LHFHOHGRX VW ULVWDELOHDOHFLUFXLWXOXLEDVFXODQWELVWDELO±&%%±VXQW

-

Starea 1FDUDFWHUL]DW Starea 2FDUDFWHUL]DW

saturat – T2 blocat . GH71 blocat – T2 saturat. GH71

2. Dimensionarea circuitului basculant bistabil cu tranzistoare &LUFXLWXO WUHEXLH DVWIHO GLPHQVLRQDW vQFkW FHOH GRXD VW UL DOH VDOH V  ILH VWDELOH  GDWRULW VLPHWULHL FLUFXLWXOXL YRP DQDOL]D QXPDL XQD GLQWUH FHOH GRXD VW UL ILH DFHDVWD GH H[HPSOX VWDUHD&RQGL LLOHFDUHVHLPSXQSHQWUXFDDFHDVW VWDUHV ILHVWDELO VXQW

1. Presupunând T1VDWXUDWWUHEXLHV UH]XOWH72 blocat. 2. Presupunând T2EORFDWWUHEXLHV UH]XOWH71 saturat. ÌQ DFHVW IHO FHOH GRX  WUDQ]LVWRDUH VH PHQ LQ XQXO SH FHO ODOW OD XQ QLYHO GH FRQGXF LH FH FRUHVSXQGH VW ULL  úL I U  YUHR LQWHUYHQ LH GLQ H[WHULRU GXUDWD VW ULL  GHYLQH QHOLPLWDW  ÌQ FHOH FH XUPHD]  GDWRULW  VLPHWULHL FLUFXLWXOXL vQ QRWD LD FRPSRQHQWHORU YRP UHQXQ D OD LQGLFHOH  VDX  GLQ FRQVLGHUHQWH GH VLPSOLWDWH úL JHQHUDOL]DUH  DVWIHO F  GH H[HPSOX

.

UH]LVWHQ HOHYRUILQRWDWH5UúL5C

9RPDQDOL]DGLVWLQFWFHOHGRX LPSOLFD LLGHPDLVXV

3ULPDLPSOLFD LH

: presupunând T1VDWXUDWWUHEXLHV

)LHVLWXD LDvQFDUH71

UH]XOWH72

blocat.

este saturat, fig. 2.

9RP FDOFXOD WHQVLXQHD GLQ ED]  WUDQ]LVWRUXOXL 72 QRWDW  8B2  úL YRP LPSXQH FRQGL LD FD DFHDVWD V  DLED R DVWIHO GH YDORDUH vQFkW V  UH]XOWH EORFDUHD OXL 72 PDL PLF  GHFkW 8  VDX úL PDLVLJXUPDLPLF GHFkW 

2

6H

FDOFXOHD] 

I2 =

r <

R



úL

+ EB r

< 0 ceea ce duce la

EB

(1)

U CE sat

+ I CBO R Presupunând UCE sat

UHOD LD GHYLQH

EB I CBO 2EVHUYD LH : Pentru blocarea lui T2DUIL IRVWVXILFLHQWV r

BE

U CE sat − U BE

Din I1 + ICBO = I2VHFDOFXOHD] U CE sat −U BE U + EB + I CBO = BE de unde R r E  1 1  U CE sat + I CBO − B U BE  +  = R r R r

Fig. 2. CBB-ul cu tranzistorul T1 saturat ÌQXOWLPDUHOD LHLPSXQHP8BE

U

I1 =

<

(2)

VH LPSXQ  FRQGL LD 8BE

< U  ([LVWHQ D VXUVHL (B

FDUHQHJDWLYHD] ED]DDSHUPLVvQV  LPSXQHUHDXQHLFRQGL LL8BEFDUHDVLJXU  R EORFDUH

mai ferma pentru T2. Deci rolul sursei EB este acela de a asigura o mai mare imunitate la zgomot a CBB-ului. (în general EBVHDGRSW GHYDORDUHPLF 9  ,PSOLFD LDDGRXD

: presupunând T2EORFDWWUHEXLHV

UH]XOWH71

saturat.

)LHVLWXD LDvQFDUHWUDQ]LVWRUXO72

este blocat,

ILJ 6H YD FDOFXOD FXUHQWXO GH ED]  ,B  úL GLVWLQFW FXUHQWXO V X GH FROHFWRU ,C  úL DSRL YRPLPSXQHFRQGL LDGHVDWXUD LH ,B

> IC .

6HFDOFXOHD]

E C = RC I C 2 + RI 1 + U BE sau

EC = RC ( I1 + I CBO ) + RI 1 + U BE de unde se

EC − U BE − I CBO RC R + RC U + EB Dar I 2 = BE úLGHFL r scoate I 1 =

Fig. 3. CBB-ul cu tranzistorul T2 blocat

I B = I1 − I 2 =

EC − U BE − I CBO RC U BE + E B − R + RC r

8UPHD] V VHFDOFXOH]HFXUHQWXOGHFROHFWRUSHQWUX71

&RQGL LDGHVDWXUD LHUHYLQHOD

3

: IC =

EC − U CE sat RC

 E − U BE − I CBO RC U + EB − BE β  C R + RC r 

 E C − U CE sat  > RC 

'H UHJXO  DFHDVW  LQHJDOLWDWH VH UH]ROY  vQ OHJ WXU  FX UH]LVWHQ D 5 úL VH

LQH FRQW GH

= 0, UBE << EC úL8CE sat = 0 : βEC R< − RC EC E B + U BE +β RC r

QHJOLM ULOH,CBO

(3)

8OWLPDUHOD LH DMXW  OD GLPHQVLRQDUHD UH]LVWHQ HL 5 ÌQV  SHQWUXR PDL EXQ  HYDOXDUH D DFHVWHL UH]LVWHQ HYRPOXDvQHYLGHQ

úLXUP WRDUHOHFRQVLGHUD LL

: 1. Se va calcula tensiunea din colectorul tranzistorului blocat, fig. 2. E − U BE E R + U BE RC U C = U BE + C R= C R + RC R + RC

2EVHUYD LH

(4)

 UH]XOW  8C = UBE = EC. Deoarece tensiunea din colectorul tranzistorului saturat

6HREVHUY F 8C,FD IXQF LHGH5HVWHR IXQF LH FUHVF WRDUH  SHQWUX 5

iar pentru R



∞  UH]XOW

 8C

HVWH  VH LPSXQH FD WHQVLXQHD GLQ FROHFWRUXO WUDQ]LVWRUXOXL EORFDW WUHEXLH V  ILH FkW PDL DSURSLDW  GH VXUVD (C FkW PDL PDUH GLVWDQ

mare. 2.

 vQWUH FHOH GRX  VLWXD LL  GHFL 5 V  ILH FkW PDL

&RQGL LD GHFDOFXO SHQWUX 5 SURYLQH GLQ LQHJDOLWDWHD VSHFLILF  VDWXUD LHL 

,B

> IC .

3HQWUXFDWUDQ]LVWRUXOV QXILHVXSUDVDWXUDWYLWH] OHQW GHFRPXWD LH VHLPSXQHFDUH]LVWHQ D 5V VDWLVIDF UHOD LD ODOLPLW 

ÌQFRQFOX]LHDPEHOHREVHUYD LLUHFRPDQG FD LQHJDOLWDWHD GHFDOFXOSHQWUXUH]LVWHQ D 5 V ILH VDWLVI FXW  OD OLPLW  &X YDORUL QXPHULF X]XDOH UH]LVWHQ D 5 UH]XOW  PXOW PDL PDUH GHFkW

.

UH]LVWHQ DGHFROHFWRU5C

3. variante de circuite basculante bistabile cu tranzistoare 6FKHPD DQDOL]DW  vQ ILJ  SUH]LQW  R YDULDQW  FRPSOHW  GH &%% ÌQ ILJ  VXQW SUH]HQWDWH

unele variante simplificate ale CBB-urilor.

Fig. 4. Variante de CBB-uri cu tranzistoare a.

ÌQ SULPD YDULDQW  GLQ FRQVLGHUHQWH GH HFRQRPLH VH SURSXQH UHQXQ DUHD OD

sursa EBÌQDFHVWFD]FRQGL

LDGHEORFDUHDWUDQ]LVWRUXOXLFXFDUHVDFDOFXODWUH]LVWHQ DUYH]L

UHOD LD VHYDLPSXQH8BE8 

4

b.

2 YDULDQW  úL PDL VLPSO  VH RE LQH GDF  VH UHQXQ

 úL OD UH]LVWHQ HOH U 5H]XOW

WRWXúLYDULDQWDFHDPDLH[SXV ODSHUWXUED LLÌQDFHVWFD]FRQGL LD UHYLQHOD5 5C

c.

9DULDQWD FHD PDL VLPSO  VH RE LQH GDF  VH UHQXQ

– RC .

 úL OD UH]LVWHQ D 5 ÌQ DFHVW

FD] WHQVLXQHD GLQ FROHFWRUXO WUDQ]LVWRUXOXL EORFDW YH]L UHOD LD   HVWH 8BE

= 0,7 V.

'H]DYDQWDMXO SULQFLSDO DO DFHVWHL VROX LL HVWH GLIHUHQ D SUHD PLF  GLQWUH WHQVLXQHD GLQ

colectorul tranzistorului saturat UCE sat úLWHQVLXQHDGLQFROHFWRUXOWUDQ]LVWRUXOXLEORFDWFDUH este egala cu UBE   9 'DWRULW  VLPSOLW LL VDOH DFHDVW  YDULDQW  HVWH DGRSWDW  XQHRUL vQ implementarea circuitelor logice bipolare. d. Transpunerea variantei anterioare în cazul circuitelor MOS conduce la ultima YDULDQW  SUH]HQWDW  XQGH UH]LVWHQ D GH VDUFLQD SRDWH IL UHDOL]DW  vQ GLYHUVH PRGXUL YH]L FLUFXLWHOHQ026úL&026 

Comanda circuitelor basculante bistabile cu transzistoare ,HúLUHD XQXL &%% VH UHDOL]HD]  GLQ FROHFWRUXO WUDQ]LVWRUXOXL 71

sau T2 ÌQ PRG WUDGL

LRQDO

LHúLUHD &%%XOXL VH QRWHD]  FX OLWHUD 4 ,HúLUHD GLQ FHO ODOW FROHFWRU VH YD QRWD FX OLWHUD 4¶ 'DWRULW  VLPHWULHL FLUFXLWXOXL RULFDUH GLQWUH FHOH GRX  FROHFWRDUH SRDWH IL DOHV GUHSW LHúLUH 4 LDURSXVXOV XYDU PkQHLHúLUHD4¶ 3ULQ

DQDORJLH

FX

FLUFXLWHOH

ORJLFH

VH

REVHUY 

F 

LHúLUHD

4

SRDWH

DYHD

WHQVLXQHD

FRUHVSXQ] WRDUH QLYHOXOXL +LJK  VDX /RZ 6HREVHUY  GH DVHPHQHD F  LHúLUHD 4¶ DUH QLYHOXO ORJLF LQYHUVDWID

Q’= Q . În fine, în limbajul uzual, când ne referim  XQ &%% vQ ORF GH VWDUHD  71 VDWXUDW úL 72 blocat) sau starea 2 (T1

GH LHúLUHD4úLGHDFHHD

OD VWDUHD vQ FDUH VH DIO

EORFDW úL 72 VDWXUDW  VH YD VSXQH F  DFHVWD VH DIO  vQ VWDUHD 4

  ORJLF  VDX 4

 /RZ

respectiv starea Q = 1 logic (sau Q = High). Circuit basculant bistabil de tip RS 8QXL DVWIHO GH ELVWDELO L VH PDL VSXQH úL  &%% FX FRPDQG  FX LPSXOVXUL SH F L VHSDUDWH vQ

baze, fig 5.

Fig. 5. CBB de tip RS &RQVWUXF LD &LUFXLWXOEDVFXODQWELVWDELOHVWHUHSUH]HQWDWvQYDULDQWDFHDPDLFRPSOHW 3RDWHILUHDOL]DWúLvQ

5

oricare dintre variantele simplificate. &LUFXLWXO DUH GRX  LHúLUL FRPSOHPHQWDUH GLQ FROHFWRDUHOH FHORU GRX  WUDQ]LVWRDUH FDUH VXQW QRWDWH 4 úL 4¶  $OHJHUHD LHúLULL 4 HVWH DOHDWRDUH GDU RGDW  IL[DW  DFHDVWD LHúLUH QRWDUHD LQWU ULORUúLDFHOHLODOWHLHúLULGHYLQREOLJDWRULL

'HQXPLUHDSHQWUXFHOHGRX LQWU ULVHPQLILF PRGXOORUGHIXQF LRQDUH

-

SET = punere pe 1 logic a CBB-ului ( respectiv Q = High ). RESET = punere pe 0 logic a CBB-ului ( respectiv Q = Low).

3HQWUX LHúLUL VH IRORVHúWH R ORJLF  GH QLYHO vQ WLPS FH SHQWUX LQWU UL VH IRORVHúWH R ORJLF  GH

impuls (comanda bistabilului este cu impulsuri): - intrare = 1 logic ⇔ SUH]HQ DXQXLLPSXOVGHFRPDQG  - intrare = 0 logic ⇔ DEVHQ DXQXLLPSXOVGHFRPDQG  &LUFXLWXO GH FRPDQG  HVWH FRPSXV GLQ GRX  JUXSXUL GH GLIHUHQ LHUH LGHQWLFH 5d1

Cd2 XUPDWH GH GRX

, Cd1 úL 5d2,

 GLRGH  '1 úL UHVSHFWLY '2 FRQHFWDWH VSUH ED]HOH FHORU GRX  WUDQ]LVWRDUH

8QHRUL VH FRQHFWHD]  úL VXUVD GH SRODUL]DUH (P

(de valoare 2 – 3 V) pentru ca în regim

VWD LRQDU FHOH GRX  GLRGH V  ILH XúRU SRODUL]DWH LQYHUV VH P UHúWH vQ DFHVW IHO LPXQLWDWHD OD ]JRPRW (YLGHQWFLUFXLWXOIXQF LRQHD] úLSHQWUX(P

= 0.

)XQF LRQDUH )XQF LRQDUHD&%%XOXL HVWHGHVFULV  GH WDEHOXO GH IXQF LRQDUH ILJ ÌQ DFHVWWDEHO LQGLFHOH Q DWDúDWLHúLULL4VHPQLILF VWDUHDLHúLULLvQDLQWHGHFRPDQG  vQWLPSFH LQGLFHOH Q VHPQLILF VWDUHDLHúLULLGXS FRPDQG ÌQ ILQHvQWRWWLPSXOIXQF LRQ ULL LHúLUHD4¶HVWHFRPSOHPHQWDUD LHúLULL4PRWLYSHQWUXFDUHQXVHPDLIDFHQLFLRUHIHULUHODDFHDVW LHúLUH

&RQIRUPWDEHOXOXLGHIXQF LRQDUHGHRVHELPXUP WRDUHOHVHFWRDUH

•

Sectorul I pentru care R = S = 0 vQ DFHVW FD] QX VH DSOLF

 LPSXOV GH FRPDQG  QLFL OD

LQWUDUHD 5 QLFL OD 6 (YLGHQW VWDUHD LHúLULL 4 U PkQH QHPRGLILFDW  DGLF  4n

= Qn+1 ( fie

HJDO FXILHFX 3HXQGHYDGHRDUHFHQXVHDSOLF QLFLXQLPSXOVGHFRPDQG  vQ PRG LPSURSULX VH QRWHD]  VWDUHD LHúLULL FX LQGLFHOH Q úL UHVSHFWLY Q 6H IDFH WRWXúL DFHDVW QRWD LHSHQWUXF HVWHIRORVLW úLvQFD]XOELVWDELOHORULQWHJUDWHVLQFURQH

•

6HFWRUXO,,SHQWUXFDUH5

úL6

vQDFHVWFD]VHDSOLF LPSXOVGHFRPDQG QXPDLOD

intrarea S. Acest impuls este derivat de grupul Rd2, Cd2, în catodul diodei D2RE LQkQGXVH R SHUHFKH GH LPSXOVXUL XQXO SR]LWLY úL XQXO QHJDWLY 'LRGD SHUPLWH QXPDL impulsului negativ V  WUHDF  VSUH ED]D OXL 72. Impulsul negativ ajuns în baza tranzistorului npn este GHQDWXU V GHWHUPLQH EORFDUHDDFHVWXLDÌQ IXQF LHGHVWDUHDLHúLULL4 vQDLQWHGHFRPDQG GHFLvQIXQF LHGH4n VHGHRVHEHVFGRX VLWXD LL

-

în linia trei a tabelului Qn

DGLF 72 HVWHVDWXUDW ,PSXOVXO QHJDWLY EORFKHD]  SH 72

úL LQL LDOL]HD]  XQ SURFHV GH EDVFXODUH SHQWUX ELVWDELO vQ XUPD F UXLD DFHVWD WUHFH vQ

-

starea Q = 1. în linia patru a tabelului Qn

DGLF 72

este blocat; Impulsul negativ cu atât mai mult

EORFKHD]  SH 72 úL QX LQL LDOL]HD]  QLFL XQ SURFHV GH EDVFXODUH SHQWUX ELVWDELO DFHVWD U PkQkQGvQVWDUHD4



ÌQFRQFOX]LHGXS FRPDQGD5

úL6

FXVLJXUDQ

ELVWDELOXOVH YDJ VL vQVWDUHD4n+1

=

 $FWLYDUHD LQWU ULL 6HW GXFH QHFRQGL LRQDW ELVWDELOXO vQ VWDUHD  ORJLF úL GH DLFL UH]XOW  úL GHQXPLUHDSHQWUXDFHDVW LQWUDUH

•

6HFWRUXO,,,SHQWUXFDUH5

úL6

2DQDOL] VLPLODU FX FHD I FXW  SHQWUX VHFWRUXO

,, YH]L VLPHWULD FLUFXLWXOXL  FRQGXFH OD FRQFOX]LD F  vQ XUPD DFWLY ULL LQWU ULL 5HVHW FX VLJXUDQ

ELVWDELOXOHVWHWUHFXWvQVWDUHD4n+1

6

GHXQGHúLGHQXPLUHDLQWU ULL 

•

6HFWRUXO,9SHQWUXFDUH5

úL6

ÌQDFHVWFD]VH DSOLF  LPSXOVXUL DEVROXW LGHQWLFH

úLVLPXOWDQHSHDPEHOHLQWU UL,PSXOVXULOHVXQWGHULYDWHLGHQWLFJUXSXULOHGHGHULYDUHVXQW úLHOHLGHQWLFH LDULPSXOVXULOHQHJDWLYHRE LQXWHGXS GHULYDUHWUHFSULQFHOHGRX GLRGH vQ ED]HOH WUDQ]LVWRDUHORU ,PSXOVXULOH EORFKHD]  VLPXOWDQ FHOH GRX  WUDQ]LVWRDUH SHQWUX R IUDF LXQHGHWLPSGDUGXS GLVSDUL LDLPSXOVXULORUFLUFXLWXOYDHYROXDFXHJDO SUREDELOLWDWH ILH vQ VWDUHD 4

  ILH vQ VWDUHD 4

  6WDUHD ILQDO  D FLUFXLWXOXL ILLQG QHGHWHUPLQDW  vQ

WDEHOXO GH IXQF LRQDUH VD VSHFLILFDW DFHVW OXFUX vQ PRG FRUHVSXQ] WRU VHPQXO GH vQWUHEDUH úLVHWUDJHFRQFOX]LDF HVWHLQWHU]LV RDVWIHOGHFRPDQG

.

Circuit basculant bistabil de tip JK 8QXL DVWIHO GH ELVWDELO L VH PDL VSXQH úL  &%% FX FRPDQG  FX LPSXOVXUL SH F L VHSDUDWH vQ

colectoare, fig 6.

Fig. 6. CBB de tip JK &RQVWUXF LD ùL vQ DFHVW FD] FLUFXLWXO EDVFXODQW ELVWDELO D IRVW UHSUH]HQWDW vQ YDULDQWD FHD PDL FRPSOHW  (O SRDWHILUHDOL]DWúLvQRULFDUHGLQWUHYDULDQWHOHVLPSOLI LFDWH 6H REVHUY  F  FHOH GRX  GLRGH '1 úL '2 FDUH VHOHFWHD]  LPSXOVXULOH QHJDWLYH UH]XOWDWH GXS

derivare sunt polarizate cu tensiune +EC vQ FDWRG SULQ LQWHUPHGLXO UH]LVWHQ HORU GH GHULYDUH  În anod, una diode are aproximativ tot +EC FHDFDUHHVWHOHJDW  ODWUDQ]LVWRUXOEORFDW vQWLPS FH FHDODOW  GLRG  DUH vQ DQRG SRWHQ LDOXO PDVHL FHD FDUH HVWH OHJDW  OD WUDQ]LVWRUXO VDWXUDW  $FHDVWD D GRXD GLRG  HVWH SXWHUQLF SRODUL]DW  LQYHUV úL GLQ DFHDVW  FDX]  QX SHUPLWH WUHFHUHD QLFLDLPSXOVXOXLQHJDWLYÌQFRQFOX]LHDPEHOHGLRGHGHFRPDQG VHOHFWHD]  LPSXOVXO QHJDWLY RE LQXW GXS  GHULYDUH GDU GLQWUH HOH XQD HVWH SXWHUQLF SRODUL]DW  LQYHUV úL QX SHUPLWH QLFL P FDUDFHVWXLDVDWUHDF PDLGHSDUWH

)XQF LRQDUH &RQIRUPWDEHOXOXLGHIXQF LRQDUHGLQILJGHRVHELPXUP WRDUHOHVHFWRDUH

•

Sectorul I pentru care J = K = 0 vQ DFHVW FD] QX VH DSOLF

 LPSXOV GH FRPDQG  QLFL OD

LQWUDUHD-QLFLOD.6WDUHDLHúLULL4U PkQHQHPRGLILFDW DGLF 4n

•

= Qn+1ILHHJDO

FX

fie cu 1). 6HFWRUXO,,SHQWUXFDUH5

úL.

vQDFHVWFD]VHDSOLF  LPSXOV GH FRPDQG  QXPDL

la intrarea K. Acest impuls este derivat de grupul Rd2, Cd2,úLvQFDWRGXOGLRGHL'2VHRE

LQH

RSHUHFKHGHLPSXOVXULXQXOSR]LWLYúLXQXOQHJDWLYÌQFHHDFHSULYHúWHSRODUL]DUHDGLRGHL

D2VHGHRVHEHVFVLWXD LLOH

7

-

în linia trei a tabelului Qn

  DGLF  72 HVWH VDWXUDW úL LPSOLFLW '2 SXWHUQLF EORFDW 

,PSXOVXOQHJDWLYRE LQXWGXS GHULYDUHQXWUHFHSULQGLRG úLGHFLVWDUHDELVWDELOXOXLVH

-

S VWUHD] DGLF 4 n+1 = 0. în linia patru a tabelului Qn

  DGLF  72 HVWH EORFDW úL LPSOLFLW '2 EORFDW   OD OLPLW 

,PSXOVXO QHJDWLY RE LQXW GXS  GHULYDUH

de accelerare C2 úL VH DSOLF

trece SULQ GLRG

 DSRL WUHFH SULQ FRQGHQVDWRUXO

 vQ ED]D OXL 71 VDWXUDW ,PSXOVXO ILLQG QHJDWLY LQL LD]

SURFHVXOGHEDVFXODUHvQXUPDF UXLDELWDELOXOWUHFHvQVWDUHD4n+1 ÌQFRQFOX]LHGXS FRPDQGD-

•

úL.

6HFWRUXO,,,SHQWUXFDUH-

FXVLJXUDQ

úL.

= 0.

ELVWDELOXOYDWUHFHvQVWDUHD4n+1

= 0.

2DQDOL] VLPLODU FX FHD I FXW  SHQWUX VHFWRUXO

,, YH]L VLPHWULD FLUFXLWXOXL  FRQGXFH OD FRQFOX]LD F  vQ XUPD DFWLY ULL LQWU ULL - FX VLJXUDQ

•

ELVWDELOXOHVWHWUHFXWvQVWDUHD4n+1

6HFWRUXO,9SHQWUXFDUH-

úL.

= 1.

ÌQDFHVWFD]VH DSOLF  LPSXOVXUL DEVROXW LGHQWLFH

úLVLPXOWDQHSHDPEHOHLQWU UL,PSXOVXULOHVXQWGHULYDWHLGHQWLFJUXSXULOHGHGHULYDUHVXQW úL HOH LGHQWLFH  LDU LPSXOVXULOH QHJDWLYH RE LQXWH GXS  GHULYDUH J VHVF FHOH GRX  GLRGH vQ VLWXD LLGLIHULWH

-

vQ OLQLD úDSWH D WDEHOXOXL 4 n

  úL LPSOLFLW '2 HVWH SXWHUQLF EORFDW  LDU '1 EORFDW  OD

OLPLW  WUHFH PDL GHSDUWH QXPDL LPSXOVXO QHJDWLY GH OD LQWUDUHD - úL FDUH DSRL SULQ

-

condensatorul de accelerare, ajunge în baza lui T2 LQL LDOL]kQG SURFHVXO GH EDVFXODUH D CBB-ului în starea Qn+1 = 1. în linia opt a tabelului Qn   úL LPSOLFLW '2 HVWH EORFDW  OD OLPLW  LDU '1 puternic EORFDW  WUHFH PDL GHSDUWH QXPDL LPSXOVXO QHJDWLY FDUH SURYLQH GH OD LQWUDUHD .

Acesta ajunge prin condensatorul de accelerare în baza lui T1 LQL basculare a CBB-ului în starea Qn+1 = 0.

LDOL]kQG SURFHVXO GH

ÌQ FRQFOX]LH GDWRULW  VHOHF LHL VXSOLPHQWDUH UHDOL]DW  SULQ SRODUL]DUHD DGHFYDW  D FHORU GRX GLRGHGHFRPDQG DFWLYDUHDVLPXOWDQ DFHORUGRXDLQWU UL- RSXV ID

.

WUHFHELVWDELOXO

în starea

GHVLWXD LDH[LVWHQW vQDLQWHGHFRPDQG 

&%%XO GH WLS -. DUH R IXQF LRQDUH VLPLODU VLPLODUFX5 vQSOXV ID

cu bistabilul de tip RS ( J similar cu S, iar K

GHDFHVWDELVWDELOXO-.UH]ROYkQGúL VLWXD LDGHQHGHWHUPLQDUHGH OD

56SHQWUXDFHDFRPDQGDQHSHUPLV  OD56ELVWDELOXO-.WUHFHvQVWDUHDRSXV ID

GHVLWXD LD

vQ FDUH VH DIO  ÌQWUXQ VHQV VH SRDWH VSXQH F  ELVWDELOXO -. UHSUH]LQW  R ³JHQHUDOL]DUH´ D

bistabilului RS. Circuit basculant bistabil de tip T ÌQILJHVWHSUH]HQWDWFLUFXLWXOEDVFXODQWELVWDELOFXFRPDQG SHRFDOHFRPXQ vQED]H

&RQVWUXF LD %LVWDELOXO D IRVW UHSUH]HQWDW FX VFKHPD HOHFWURQLF  FHD PDL FRPSOHW  GDU SRDWH IL UHDOL]DW vQ

oricare din variantele simplificate. &HOH GRX  GLRGH GH FRPDQG  VXQW SRODUL]DWH SULQ LQWHUPHGLXO UH]LVWHQ HORU GH GHULYDUH FX SRWHQ LDOXO GLQ FROHFWRUXO WUDQ]LVWRDUHORU UHDOL]kQGXVH vQ DFHVW IHO R VHOHF LH VXSOLPHQWDU  D GLRGHORUVLPLODU FHOHLUHDOL]DWHODELVWDELOXO-.

-

pentru starea Q = 0, tranzistorul T2 este saturat iar T1 HVWH EORFDW SRWHQ LDOXO GLQ colectoarele tranzistoarelor este transmis în catodul diodelor astfel încât dioda D2 este

-

SHQWUXVWDUHD4

EORFDW ODOLPLW LDU'1HVWHSXWHUQLFEORFDW  RDQDOL] VLPLODU FRQGXFHODFRQFOX]LDF GLRGD'1HVWHEORFDW OD

OLPLW LDU'2HVWHSXWHUQLFEORFDW 

8

)LJ&%%GHWLS7FXFRPDQG SHRFDOHFRPXQ vQED]H )XQF LRQDUH &RQIRUPWDEHOXOXLGHIXQF LRQDUHGLQILJGHRVHELPXUP WRDUHOHVHFWRDUH

• •

Sectorul I pentru care T = 0vQDFHVWFD]QXVHDSOLF LPSXOVGHFRPDQG ODLQWUDUHD7. 6WDUHDLHúLULL4U PkQHQHPRGLILFDW DGLF 4 n = Qn+1ILHHJDO FXILHFX  Sectorul II pentru care T = 1vQDFHVWFD]VHDSOLF XQ LPSXOVGHFRPDQG  OD LQWUDUHD7 Acest impuls este derivat identic de ambele grupuri de derivare Rd1, Cd1 úL UHVSHFWLY 5d2, Cd2.,PSXOVXULOHRE LQXWHGXSDGHULYDUHJ VHVFFHOHGRX GLRGHvQVW ULGLVWLQFWH - pentru linia trei a tabelului Qn   DGLF  '2 XúRU EORFDW  LDU '1 SXWHUQLF EORFDW  ,PSXOVXO QHJDWLY RE LQXW GXS  GHULY UL WUHFH QXPDL SULQ GLRGD '2 úL DPRUVHD]

-

procesul de basculare al bistabilului determinând trecerea acestuia în starea Qn+1 = 1. pentru linia patru a tabelului Qn   DGLF  '2 SXWHUQLF EORFDW  LDU '1 XúRU EORFDW



,PSXOVXO QHJDWLY RE LQXW GXS  GHULY UL WUHFH QXPDL SULQ GLRGD '1 úL DPRUVHD]

procesul de basculare al bistabilului determinând trecerea acestuia în starea Qn+1 = 0. ÌQFRQFOX]LHFRPDQGD7 WRJJOH

 WUHFH ELVWDELOXO vQ VWDUHDRSXV  GH XQGH úL QXPHOH LQWU ULL  7

 EDVFXODUH  6H REVHUY  F  LQWUDUHD 7 DF LRQHD]  VLPLODU FX R FRPDQG  -

ELVWDELOXO-.FDúLFXPLQWU ULOH-ú.DUILOHJDWHvPSUHXQ úLUHERWH]DWHFX7 

)LJ&%%GHWLS7FXFRPDQG SHRFDOHFRPXQ vQFROHFWRDUH

9

 . SHQWUX

ÌQILJVDSUH]HQWDWRDOW YDULDQW GHLPSOHPHQWDUHSHQWUX&%%XOGHWLS7FDUHSURYLQH SXUúLVLPSOXGLQELVWDELOXOGHWLS-.SULQOHJDUHDvPSUHXQDDFHORUGRX LQWU UL)XQF LRQDUHD DFHVWXLDGHULY HYLGHQWGLQIXQF LRQDUHDELVWDELOXOXLGHODFDUHVHSOHDF 

10